Db Definition and 62 Threads

Does anyone know how to filter 60 hz down to -140 db all the notch filters I tried are about -60 db maximum but after I amplify the signal to 100db the 60 hz becomes a problem again. I need a filter for this it doesn't have to be one stage and also I need the 100hz, maximum attenuation on 100...

Homework Statement Two sounds differ in sound level by 2.80 dB. By what factor is the one intensity greater than the other? Homework Equations The Attempt at a Solution Is the equation B = 10dB log(I/Io) relevant?

Amp "A" - 250W, Amp "B" - 40W a) Estimate sound level in dB you would expect at a point of 3.5m from a speaker connected to each amplifier. I think the formula to start with is to convert watts to decibels(B). B = 10xlog (I/1x10[SUP]-12) okay the superscript isn't working...that's I...

can anyone describe wat is dB level. can dB level be showed through receiver or field strength meter? thx for helping

i personally think that this is just a very simple problem since the problem only requires plugging the right values into the formula. I'm just having trouble with one minor detail. Homework Statement For the current element Idx(ax+ay) A situated at P(1,-2,2), find the magnetic flux...

'The intensity level of sound in a factory is 93.0 dB when all seven of its machines are working. If four machines are shut down for maintenance, what is the intensity level of the sound from the remaining machines? Assume that all seven machines are identical.' I know the answer is not just...

hi, I'm having trouble with a question and i was wondering if anyone can help me out. "To a person who is hard of hearing, normal conversation (60dB) sounds like a soft whisper. What increase in sound levels (in dB) must a hearing aid provide? How many times must the sound wave pressure be...

Is the x-axis of a Bode plot supposed to be angular frequency omega or just the frequency f? The y-axis is in dB. Thanks!

Hello all, I am having trouble figures out the following filter I am designing. I to use a filter with a 24db/oct slope I want 0dB@90hz. So if I want the knee of the cuttof curve to start at 90Hz how do I find the -6dB point so I can design the crossover, by the way this filter uses -6dB as the...

I've been watching a discussion on another forum regarding the use of loud horns to deter dogs from chasing bikes. Some dissenters say that it is cruel since dogs can "hear so much better than humans" and such loud sounds can injure them. My question is, is it better stated that dogs have a...

Hi I´m a little bit confused regarding conversion to dB: Regulations for a project I´m on say the maximum magnetic field strength allowed is 60 dBuA/m at 10 m. (here I chose 60 myself for simplicity...) So the question is will this correspond to 1 A /m at 10 m (10log[1000000/1]=60 dB)...

A portable radio is sitting at the edge of a balcony 5.1m above the ground. The unit is emitting a sound uniformly in all directions. By accident, it falls from rest off the balcony and continues to play all the way down. A gardener is working in a flower bed directly below the falling unit...